If you read
LASORs (big download) from the UK CAA SRG site you'll find that it is accurate.
Essentially, if you have a total time of a minimum 3,000 hours and 1,500 hours in command of aircraft greater than 30,000kg in primarily international scheduled or similar operations then you only need to do 2 exams plus a sim ride. (Air Law and Human Performance & Limitations)
However, your ATPL will be valid for G-reg aircraft only. If you want to fly for a non UK airline, you'll have to comply with that state's regs, (ie do the rest of the exams)
See Section G, G1.5 Note 2.